Views:4 Author:Site Editor Publish Time: 2019-12-08 Origin:Site
Almost all walkie-talkies have high, medium and low transmission powers which can be adjusted. For the handset, the transmit power can generally be selected between 0.5 ~ 5W; the car station can be selected between 10W ~ 40W. If there is obvious noise when using low-power communication, switch to a higher transmission power to improve communication quality and extend a certain communication distance. Theoretically, the transmission power is doubled, and the communication distance can be extended to about 1.4 times the original distance. However, if the transmission power is increased at random, it will also bring negative effects such as increased power consumption, increased electromagnetic radiation and interference.
The increase in antenna height is very effective for extending the communication distance. Without increasing the transmission power, each doubling of the receiving and transmitting antennas can also increase the communication distance to about 1.4 times, which is both economical and environmentally friendly. There have been tests: a pair of handheld phones with an outdoor communication distance of about 4 kilometers in the urban area, and one of them was carried on the top of a mountain about 100 kilometers away from the urban area. This walkie-talkie can still communicate with the walkie-talkie in the urban area.
The receiving sensitivity of the two-way radio has a great influence on the communication distance. Generally, when the two-way radio is delivered, the sensitivity has been adjusted to the best state according to relevant technical requirements. Without professional equipment and technical personnel, you must not adjust the two-way radio's receiving sensitivity by yourself. For the user, in addition to adjusting the squelch threshold of the radio, the receiving sensitivity of the radio can also be improved by switching to a high-gain antenna. When changing the antenna, you should pay attention to the antenna of the same frequency band (antennas of different frequency bands cannot be used interchangeably). Otherwise, this will not only improve the receiving sensitivity, it may even cause a large standing wave due to antenna mismatch, which will damage the RF power amplifier.
The longest communication distance given by the two-way radio manufacturers is measured under open conditions without obstacles. In this communication environment, the loss of radio wave propagation is the smallest, and the absorption of radio waves by reinforced concrete buildings in cities is relatively serious. Therefore, when using the walkie-talkie indoors, you should try to choose a position near the window. Outdoor use should avoid the obstacles of tall buildings or trees around.
Usually pay attention to often check the radio's battery power is sufficient, whether the antenna connection is firm, whether the whip antenna is fully pulled out, etc. These factors directly affect the radio's transmit power and receiving sensitivity, and thus affect the communication distance. Also, do not use a damaged or deformed antenna. Especially for the users of the mobile station, the antenna is located on the roof of the vehicle. It is easy to damage the antenna due to bumps or scraping trees during driving, resulting in a significant reduction in communication distance!